Is it possible to have dynamic routes in pion?

Question

I'd like to use pion 5.0.6 as a small webserver in a VS2017 c++ project. For static routes I can use

add_resource("/my/static/route", <handler>)

I would need dynamic routes as well - like "/data/:id/info How do I do this?

Answer 1

For those who may need it: I found a solution to add dynamic routing to the pion webserver. It requires smart router code I found at hxoht on github, and works the way that

• all routes - static and dynamic - are set with httpd->add_resource(<url>, <handler);
• a 404-handler has to be set with httpd->set_not_found_handler(<handler>); and is responsible for dispatching the dynamic routes to the handlers added above.
• your webserver class must derive from pion::http::server in order to find the handler by name with httpd->find_request_handler(<url>, <handler>);

• in your 404-handler, you use the Match::test(<dynamic-route>) method to detect a dynamic route - like in the following code fragment:

  void handle_404(http::request_ptr& req, tcp::connection_ptr& con)
  {
      Route target;
      Match dynamic = target.set(req->get_resource());
      for (auto& route : dynamic_routes) // Our list of dynamic routes
      {
          if (dynamic.test(route)) // Does the url match the dynamic route pattern?
          {
              request_handler_t h;
              if (find_request_handler(route, h))
              {
                  auto name = get_param_name(route); // e.g. /a/:b -> "b"
                  value = dynamic.get(name); // Save value in string or map<name, value>
                  h(req, con); // Call original handler with value set properly
                  return;
              }
          }
      }
      // If no match then return a 404.
      http::response_writer_ptr w(http::response_writer::create(con, *req,
      boost::bind(&tcp::connection::finish, con)));
      http::response& res = w->get_response();
      res.set_status_code(http::types::RESPONSE_CODE_NOT_FOUND);
      res.set_status_message(http::types::RESPONSE_MESSAGE_NOT_FOUND);
      w->send();
  }
  

For using the pion webserver in a multi-threaded way, I would store the parsed value inside the request object, which would be derived from pion::http::request.

This would work for Windows and Linux :)